An armature of an electric motor is generally provided with a core and a winding wound around the core. The winding is composed of a plurality of wires bundled together, and has a plurality of coil parts formed into the shape of a coil and connecting portions for connecting the coil parts together. The core is provided with a plurality of slots and has a coils side of the coil parts embedded in the slots.
A method for manufacturing an armature such as that described above is disclosed in, e.g., Japanese Laid-open Patent Application No. 2005-110342.
First, a single coil part is formed by winding a winding on a winding frame. Here, a winding 110 is wound on a winding frame 130 by moving a flyer 120 for guiding the winding 110 composed of a plurality of wires W around the winding frame 130, as shown in FIG. 8. A coil part 100 is thereby formed in a shape in which a plurality of strip-shaped wires W are wound in a helical shape. Next, the coil part 100 is pressed down and out from the winding frame 130 and moved to a transfer tool 140. The transfer tool 140 is a member for mounting the winding 110 on a core 150 (see FIG. 11) and is capable of circularly arranging and holding the plurality of coil parts 100 to 107 (see FIGS. 9 and 10).
The coil part 100 described above is moved to the transfer tool 140, after which a connecting portion 111 is formed before the winding of the next coil part 101 begins. The connecting portion 111 is formed in sequence from the winding 110 forming the coil part 100, and is a portion that extends to the adjacent coil part 101. The connecting portion 111 is formed by rotatably moving the transfer tool 140 or the winding frame 130 about the axial line of the transfer tool 140. The next coil part 101 is then formed from the same winding 110 and moved to the transfer tool 140.
The above operation is repeated, and the state shown in FIG. 9 is achieved when the formation and transfer of the required number of coil parts 100 to 107 and connecting portions 111 to 117 to the transfer tool 140 have been completed. At this point, as viewed from above, a plurality of coil parts 100 to 107 are arrayed in a circle about the periphery of a stripper 141 of the transfer tool 140. Mutually adjacent coil parts 100 to 107 are formed so that the winding directions are opposite from each other.
Next, the core 150 is arranged above the transfer tool 140, as shown in FIG. 10. FIG. 10 is a cross-sectional view along the line X-X in FIG. 9. The core 150 has a plurality of slots formed in the internal peripheral surface (see FIG. 2). The coil parts 100 to 107 are lifted upward when the stripper 141 ascends. The coils sides of the coil parts 100 to 107 are thereby inserted into the corresponding slots, as shown in FIG. 11. FIG. 11 shows a state in which the coil side 121 (see FIG. 9) of the coil part 100 is inserted into the slot S100 of the core 150, and the coil side 122 (see FIG. 9) of the coil part 103 is inserted into the slot S103.